Fire box for cast-iron boilers



Jan. 14, 1930. H. E. GILBERT 1,743,129

FIRE BOX FOR' CAST IRON BOILERS Original Filed April 1925 I 2 She'ets-Sheet 1 H. E. GILBERT FIRE BOX FOR CAST IFON BOILERS Jan. 14, 1930.

2 Sheets-Sheet 2 Original Filed April 6, 1925 Patented Jan. 14, 1930 HARRY E. GILBERT, OF BRIDGEPORT, CONNECTICUT FIRE BOX non. CAST-IRON BOILERS Application filed April 6, 1925, Serial No. 20,957.

This invention relates to improvement in fire-boxes for cast-iron boilers, and particularly for boilers using oil or gas as the heating medium. In the more general construction of heaters, the hottest point is adjacent to the nozzle of the burner or at the front of the combustion-chamber, and the heat gradually diminishes as the rear of the combustion-chamber is approached. This causes an undue heatin of the boiler at the forward end and a lac of heat at the rear end, causing the sections or tubes at the forward end to burn out. The object of this invention is to provide for radiant heat, and also to provide for an equal distribution of the flames from the burner throughout the combustionchamber, and the invention consists in the construction as hereinafter described and particularly recited in the claim.

In the accompanying drawings Fig. 1 1s a front view partly in section of a cast-iron boiler provided with a fire-box embodymg my invention, and Fig. 2 is a longitudinal, sectional view of the same.

In illustrating my invention, I have shown it in connection with a boiler 5 of usual construction, including a series of sections 6. The fire-box or combustion-chamber 7 is provided with a top 8, preferably crowned, and formed from siliceous material, such as carbon silica and magnesite, for instance, and also formed with a series of apertures 9 opening into the lower part of the boiler proper.

' This top 8 is supported by side-walls 10 and 11 resting on a floor 12 supported by longitudinal walls 13 arranged in an air-chamber 14. The side-walls and end of the combustion-chamber are separated from the boilercasing by sheets of insulating material 15. At the forward end of the combustion-chamber is a throat 16 of siliceous material, formed with a flaring mouth 17, and forward of the throat is an oil or gas burner 18 of any approved construction, in line with the mouth 17. With these burners, a predetermined Renewed June 10, 1929.

amount of air is used. Below the burner is a pit 19, covered by a grating 20, this pit 19 opening into the air-chamber 14 beneath the floor 12. This floor 12 is formed fromanysultable refractory material, but laid 'with spaces 21 between the bricks 22, gradually increasing in area toward the rear of the com'- bustion-chamber. This is for the admission of secondary air to the combustion-chamber;

In use, gas from the burner 18 is discharged into the combustion-chamber under pressure, and this heats the top 8, which, in turn, radiates the heat to the boiler proper. The

openings 9 are for the passage of the products 7 of combustion, which are carried to a suitable flue. The combustion is normally best jat the forward part of the combustion-chamber, but 1 by admitting air in increasedquantities, as the;v

combustible mixture approaches'the rear end, it equalizes the combustion, so thatan equal amount of heat is obtained at the rear of the 2 chamber and atthe front. This equally heats the top 8 and, consequently, the radiance I of heat at the rear sections of the boiler is t-ion chamber, a throat at the forward end thereof,- a top arch of siliceous material formed with passages only for the products of combustion from the chamber to the boiler, a floor made of fire-bricks laid with spaces between themgradually increasing in area as they approach the rear of the said chame I V ber, a burner opening into said combustion, chamber through said throat, and means'admitting air to said chamber through the spaces in the said-floor'for the purpose of effecting a uniform temperature within the chamber and a uniform incandescence of its siliceous to the said fire-box unit being built direct y underneath the main heating surface of the boiler and extending throu hout its entire Pen th, its top being adapted to subject the main eating surfaces of the boiler to a uniform degree oi radiant heat by the uniform incandescence of the said top arch.

In testimony whereof, I have. signed this specification.

HARRY E. GILBERT. 

